Nosocomial infections account for billions of dollars in hospital costs per year. Candidiasis has become a problem of considerable importance to patients undergoing many forms of cancer therapy including immunosuppression, chemotherapy and heroic surgery. There has been only a limited amount of basic research on the antigenic composition of this yeast and the significance of antibodies produced during colonization and infection with this organism. The aims of this proposal are: 1. Quantitative immunoelectrophoric study for the antigens and antibodies produced during transformation of this organism for a yeast to a mycelial phase. 2. Isolation of various fractions of C. albicans relating antibody formation to them during colonization and throughout infection using animal models. 3. Correlating the results of the above to a human monitoring program currently in operation and for which no funds are requested.